KABUL, Afghanistan - A former American soldier convicted in Afghanistan of running a private jail and torturing terror suspects has left the country after three years in a Kabul prison, the warden said Wednesday.

Jack Idema, who received a pardon from President Hamid Karzai as part of a general amnesty, boarded a transport plane with a dog who had lived with him in prison.

Rahim Ahmadzai, his Afghan lawyer, said Idema left the Policharki prison outside Kabul on June 2 and flew out of Afghanistan. He did not know Idema's destination.

In an e-mail to The Associated Press, Idema wrote, "I can't and won't tell anyone where I am and what I am doing."

Shamir, the warden of Policharki prison where Idema was held, said the former Green Beret had wanted to stay in Afghanistan but couldn't for legal reasons. Shamir, who like many Afghans goes by one name, said he transported Idema and his dog, named Nina, to the Kabul airport for the flight out.

"He wanted to stay in Afghanistan, but there was no way for him to stay," Shamir said.

Edward P. Birsner, the consul at the U.S. Embassy in Kabul, said in court documents filed in Washington this week that Idema had left for "an unknown destination." The documents were filed in a case in which Idema accused the FBI and State Department of ordering his torture and manipulating the Afghan judicial system.

Idema's U.S. attorney, John Tiffany, would not say where Idema flew to but said he does not believe he was immediately heading to the United States.

"At some point, he'd like to come back to the United States," Tiffany said. "He's an American. He loves his country."

Idema was sentenced to 10 years in prison by a Kabul court in September 2004 on charges of entering Afghanistan illegally, making illegal arrests, establishing a private jail and torturing the captives.

Two other Americans were also convicted. Brent Bennet was sentenced to 10 years but was released in September. Freelance cameraman Edward Caraballo was sentenced to eight years; he was released in April 2006.

Some of the Afghans Idema imprisoned claimed they were beaten and their heads held under water. However, Idema says he never mistreated prisoners and the prosecution offered scant evidence at his sometimes chaotic Kabul trial.

Idema, who has maintained that his activities in Afghanistan were sanctioned by the U.S. government, claims to have fought with the Northern Alliance forces that toppled the Taliban regime in late 2001. He was featured in a book about the Afghan war called "Task Force Dagger: The Hunt for bin Laden."

The U.S. military acknowledges accepting prisoners from Idema in Afghanistan in 2004 and the separate NATO-led force there helped him with raids near Kabul.

However, the military soon denounced him as an impostor and he was arrested only a few months after entering the country.

Abdul Wahab Jwinda, an Afghan army commander who said he saw Idema off at the Kabul airport, said several Afghan military and two U.S. personnel accompanied Idema to the plane.

Jwinda said he and Idema fought against the Taliban together in eastern Afghanistan shortly after the U.S.-led invasion in 2001. Idema had tears in his eyes while saying goodbye, Jwinda said.

"I may be leaving Afghanistan, but my heart will stay in Afghanistan," he quoted Idema as saying.

Tiffany said Idema flew out of the country from the main U.S. base at Bagram. It wasn't clear if the plane flew from Kabul and then to Bagram before leaving Afghanistan.

"If this individual truly was convicted and truly did all the things they say he did, how could he leave from Bagram Air Force Base, a military airport?" Tiffany said.

Idema, who served three years in U.S. jail for fraud in the 1980s, told the AP by cell phone from Policharki last month that he had stayed in prison even after being freed because he risked arrest by Afghan intelligence agents. He said that departing would harm his chances of recovering documents, tapes and computer files that show his alleged relationship with U.S. officials.

A U.S. federal judge in April said the United States had to respond to a lawsuit by Idema alleging that the State Department and FBI illegally kept him imprisoned, directed his torture and destroyed evidence. Idema said he has audio recordings and documents to back up his claims.

The U.S. Embassy in Kabul responded by saying that since Idema had been freed by Karzai, his claims no longer had merit.

The U.S. has said it secured Idema a passport and helped him with travel information for him and the dog.